It is known in the art that the use of various specific sulfur-accelerator combinations yield rubber vulanizates having particularly desirable properties. One instance of this is the use of sulfur and 2-benzothiazole 4-morpholine disulfide (BMD) to yield vulcanizates having excellent thermal aged properties. Such vulcanizates would be extremely useful as gaskets, automotive hose and tires, and other products where good retention of properties on heat aging is needed. Unfortunately, the sulfur-BMD cure system is very fast acting, and yields quite scorchy rubber compositions having little processing safety. This prevents the use of such a cure system in operations where the vulcanizable rubber compositions must be handled and processed for extended periods at elevated temperatures, as in tire manufacturing. The use of known cure retarders provides only a marginal increase in scorch safety when employed with the sulfur-BMD cure system.